Centrifugal jaw crushers

ABSTRACT

Centrifugal jaw crusher for stone and the like, in which one jaw reciprocates relatively to the other and in which both jaws are maintained in rotation about a common axis and between which crushed material moves outwardly centrifugally during back strokes of the reciprocating jaw.

United States Patent Gauldie Sept. 5, 1972 [54] CENTRIFUGAL JAW CRUSHERS 748,867 1/1904 Hodge ..241/205 7 I t I K th G 2,663,340 12/1953 Goodwin ..241/205 X 2] g' 'gg g g' 31:3,, 3,065,919 11/1962 Burkett et a1 ..241/161 [22] Filed: June 1, 1970 Primary Examiner-Granville Y. Custer, Jr.

Attorney-Weir, Marshall, MacRae & Lamb, Harold [21] A991 42184 A. Weir, Harvey 1. Marshall, Robert A. MacRae, James A. Lamb, Lorne C. Shaw, William D. Parks and [52] US. Cl ..241/205 Angus J. S. Davidson [51] Int. CL ..B02c 2/00 [58] Field of Search ..241/205 [57] ABSTRACT Centrifugal jaw crusher for stone and the like, in [5.6] MW CM which one jaw reciprocates relatively to the other and ED STATES PATENTS in which both jaws are maintained in rotation about a common axis and between which crushed material 1,065,332 6/1913 Newhouse ..241/205 moves outwardly cenu-ifugally during k Strokes f 1,065,535 6/1913 L1eber ..241/205 the reciprocating jaw. 1,066,218 7/1913 Newhouse ..241/205 736,519 8/1903 Hodge ..241/205 3 Claims, 3 Drawing Figures I, d 4"" H- I 1.52 i T H 300/ 9 5 v PAIENTEMEP' 5 m2 3.688.994

SHEET 1 UF 2 PATENT A GEN T PATENTEDSEP 51912 3 688 994 sum 2 or 2 FIG.3

CENTRIFUGAL JAW CRUSHERS The present invention relates to crushers for stone and the like, in which the material is crushed between surfaces one of which is reciprocated towards and away from its neighbor. In this invention both surfaces are in rotation about a common axis; and material that has been crushed between them during forwardstrokes of the reciprocating jaw, moves outward and escapes centrifugally during opening strokes. The reciprocating jaw may be operated mechanically, but preferably the means is hydraulic and comprises a ram of relatively large diameter and short stroke in direct hydraulic communication with a power driven plunger of relatively low diameter and long stroke.

The invention will be described with reference to the accompanying drawing, in which:

FIG. 1 is a side elevation, partly in section of a machine in accordance with the invention,

FIG. 2 is a sectional elevation of a jaw setting control means, and

FIG. 3 shows the mounting of the torsion bar.

In order that the material to be crushed may be fed into the machine by gravity, the common axis about which the ram and its cylinder rotate, is preferably vertical, as illustrated in FIG. 1. In such machine the upward force hydraulically exerted on the ram 1, during its crushing strokes, is transmitted to the lower jaw plate 2, and thence through the material being crushed to the upper jaw plate 3, and the crusher head 4. From there the crushing force may be transmitted back to the ram cylinder through bolts surrounding the jaws. The wearing action of the escaping crushed material on such bolts might, however, be appreciable. It is therefore preferred that the head be extended cylindrically downwards round the jaws towards the ram cylinder 5, and that outflow of crushed material should be through openings 6, cast in the downward extension of the crusher head where the cross section of the metal transmitting crushing force and subject to wear by the crushed material may be large. The connection at this low level between the crusher head and the ram cylinder may be by studs. For reasons of accessibility and ease of assembly and disassembly, a bayonet joint is, however, preferred. This joint comprises a ring of projections 7, extending inwards from the crusher head, the spaces between which are somewhat greater than their width. A ring of projections 8, identical with those on the crusher head project from the ram cylinder. On assembly the projections on the crusher head pass down between and beyond those on the ram cylinder, and a subsequent slight rotation of the crusher head brings the projections into position directly opposite one another. A number of set screws 9 are provided to bring the projection into rigid contact with one another to complete the joint.

The tangential velocity of the crushed material escaping from the openings 6, in the crusher head may be considerable and means to arrest this motion and prevent projection of crushed material over a wide area are practically necessary in a machine with vertical axis. This means may comprise a fixed annular chamber 10 of U-shaped radial section into which the crushed material is projected. This material collects in the chamber as an annular ring with a conical surface 11 lying at the natural angle of about 45 to the horizontal. On this surface the crushed material impinges and is arrested and then falls vertically from the slope. It may fall into a sloping launder or trough surrounding the upper part of the machine, from which it may be delivered on to a conveyor belt or, as indicated in FIG. 1, it may fall into a chamber 12 below the machine from which it may be conveyed. A sheet metal casing surrounds the machine to prevent escape of dust from the falling material. A covered opening 30a is provided for access to the setscrews 9.

Dust may be excluded from the operating mechanism by a, bellows dust seal 32 surrounding it.

In a hydraulically operated centrifugal, crusher,

leakage of liquid occurs past ram, plunger and elsewhere where it is removed from the system with the crused ore. A given jaw setting is maintained by injection through a make-up valve, of make-up liquid at a rate equal to'the rate of leakage from the system. The construction and operation of this valve are explained in British Pat. specification No. 648,433 (Gauldie). The make-up valve 13, has'a continuous and very slow opening movement under the control of a dash pot except instantaneously at an end of every crushingstroke of the ram, when it is given a corrective movement in the closing direction by a member moving in unison with the ram. In this manner the opening through the valve is so governed by the position of the ram and moving jaw at the end of every crushing stroke that make-up enters the system at a rate equal to that of leakage, and a definite jaw setting is maintained.

The movement of the'ram during its back strokes is maintained in unison with that of the operating plunger by a spring which exercises the necessary retractive force through a rod 14, extending from and coaxial with the ram. This spring may be helical, encircling the retraction rod as is usual in crushers of swing-jaw type. A torsion rod retraction spring is, however, specially applicable to centrifugal crushers, and in the following description such spring is presumed.

The torsion rod 15 is ordinarily straight and is fixed to the casing 24 at one end against turning as shown in FIG. 3. The other end is held in a bearing 35, and a lever arm 16, extending radially from the torsion rod is pivoted to the retraction rod 14. For clarity the support structure for bearing 35 has been omitted from FIG. 1. In normal operation the torsion rod, between its fixed end and the retraction lever 16 is twisted through the angle needed to develop the necessary force on the retraction rod to accelerate the ram and jaw during back strokes and maintain their motion in unison with that of the plunger. The fixed end of the torsion rod is so held that the working position of the lever 16, is more or less horizontal. Should this working position be raised or lowered there would be corresponding change in setting of the jaws.

Lever arm 16 has a downwardly extending tappet 16' which at an end of every crushing stroke of the ram, gives a momentary corrective impulse to the make-up valve whereby a given jaw setting is maintained. For adjustment of jaw setting, a distance piece of .variable length may be interposed between tappet l6 and the stem of the make-up valve. The distance piece may be a wedge any transverse movement of which would change the working position of the retraction rod and alter the jaw setting.

Preferably, however, the distance piece is a member mounted on an extension of the make-up valve stem and movable axially along it. As illustrated in FIG. 2 the cylindrical distance piece 19, is internally threaded and is carried on a screwed extension of the valve stem 20 and is movable axially by screwing it along the stern thereby changing the working position of the control arm. The means whereby such change is made comprises a spur gear 21 on the distance piece, and a relatively long pinion 22 on a spindle 23 which may be rotated by an external handwheel. Any rotation of the spindle moves the distance piece axially along the stern whereby the working positions of the lever16, and of the ram and lower jaw, are altered and corresponding change of jaw setting is made.

The ram, the cylinder in which it rotates, and the rest of the crushing mechanism, rotatetogether, and the whole assembly is supported in a fixed housing 24 (FIG. 1) by a co-axial stem 25 extending from the end of the ram cylinder. Communication between the ram and the operating plunger, 40 shown as operating in a cylinder formed by an extension of channel 26, is made through the channel 26 and the bore 27, which extends partly through the stem and is completed through openings 29 in its wall. The total area of the cylinder subject to downward pressure is, therefore, equal to the area of the ram. The system is therefore in complete hydraulic balance, and no force other than the weight of the rotating parts is borne by the bearing on which these parts are supported. 1

FIG. 2 shows the make-up valve in greater detail. The valve stem 20 is fixed to a piston 50 which is formed with a plurality of ports 51. Needle 20 is also formed with a shoulder 52 against which a compression spring 53 bears. The spring 53 urges a disc valve 54 towards piston 50 to close ports 51. The needle 20 includes a closure portion 55 which is operable to open or close conduit 43. A compression spring 56 urges the piston and, consequently, the valve stem 20 to the left as seen in FIG. 2.

Make-up fluid is supplied to the hydraulic cylinder during the return stroke of ram -1. As can be seen in FIGS. 1 and 2, when the ram is in its upward stroke, rod and consequently lever 16 will rotate in a counterclockwise direction causing tappet 16' to engage the cylindrical distance piece'l9 and force valve stem to the right against the action of spring 56. During the a mit additional mak -u flu'd to be su lie to the system..Conversely,?ft ere i sasmallerlg so leakage fluid than expected the stroke'of ram 1 will increase and the needle valve will be driven further in its-closing direction.

I claim: l. A jaw crusher for receiving comprising a pair of jaws one being mounted on a ram cylinder for reciprocal movement with respect to the other, means for rotating said jaws about a common vertical axis whereby crushed material moves outward centrifugally during back strokes of the reciprocating jaw, a crusher head extending in anaxial directionaround the jaws having openings through which material crushed between the jaws is projected, a ring of projections each of which is less in width than the spaces between them, extending inwardly from the crusher Y head and capable of passing through and beyond an identical ring of projections extending outwardly from the ram cylinder and of being turned to bring the ring of projections opposite one another, means for bringing and maintaining the rings of projections into rigid contact with one another and a U-shaped annular chamber completely encircling the jaws, wherein crushed material forms a ring with an inwardly sloping conical surface against which material projected from the jaws impinges and is arrested, said chamber having an outlet for outflow of the crushed material.

2. A jaw crusher having one jaw which reciprocates relatively to a second jaw and is mounted on a coaxial ram in a rotating cylinder with which both jaws rotate, wherein the said cylinder is supported laterally in a fixed housing on a stem extending coaxially from the a said cylinder, the said stem having an axial bore extending partly through it, through which and through openings in its side hydraulic communication is made between the ram and a power driven reciprocating plunger.

3. A hydraulically operated jaw crusher as claimed in claim 2, in which the axis is vertical and in which a fixed U-shaped annular chamber surrounds the jaws, wherein crushed material forms a ring with inwardly sloping surface, against which material projected from the jaws impinges and is arrested and from which it falls.

and crushingmaterial 

1. A jaw crusher for receiving and crushing material comprising a pair of jaws one being mounted on a ram cylinder for reciprocal movement with respect to the other, means for rotating said jaws about a common vertical axis whereby crushed material moves outward centrifugally during back strokes of the reciprocating jaw, a crusher head extending in an axial direction around the jaws having openings through which material crushed between the jaws is projected, a ring of projections each of which is less in width than the spaces between them, extending inwardly from the crusher head and capable of passing through and beyond an identical Ring of projections extending outwardly from the ram cylinder and of being turned to bring the ring of projections opposite one another, means for bringing and maintaining the rings of projections into rigid contact with one another and a Ushaped annular chamber completely encircling the jaws, wherein crushed material forms a ring with an inwardly sloping conical surface against which material projected from the jaws impinges and is arrested, said chamber having an outlet for outflow of the crushed material.
 2. A jaw crusher having one jaw which reciprocates relatively to a second jaw and is mounted on a coaxial ram in a rotating cylinder with which both jaws rotate, wherein the said cylinder is supported laterally in a fixed housing on a stem extending coaxially from the said cylinder, the said stem having an axial bore extending partly through it, through which and through openings in its side hydraulic communication is made between the ram and a power driven reciprocating plunger.
 3. A hydraulically operated jaw crusher as claimed in claim 2, in which the axis is vertical and in which a fixed U-shaped annular chamber surrounds the jaws, wherein crushed material forms a ring with inwardly sloping surface, against which material projected from the jaws impinges and is arrested and from which it falls. 